Could a dentist refuse me treatment due to medication being against my religious beliefs?

I suppose they can..: Any healthcare provider needs to feel comfortable treating their patients, and treatment can be refused for any number of reasons. If your dentist feels he/she cannot help you without the use of medications, then there's no point in being a patient of theirs, right? You'll need to find a dentist who is willing to treat you under your terms. All the best...

Refusal to treat: Dentists cannot refuse to accept patients into their practice or deny dental service to patients because of the patient's race, creed, color, sex or national origin. However, they may exercise reasonable discretion in selecting patients for their practices. Yes, they can refuse to treat you if you do not follow their recommended advice as they become responsible for your well-being.